Observation Of Biological Characteristics And Artiifcial Propagation For Aquatic Fern Ceratopteris Thalictroides

Aquatic fern（Ceratopteris thalictroides (L.)Brongn）is now endangered and islisted among the second category of the State Important Protected Wild Plants inChina. A newly-recorded place of aquatic fern was found. The finders studied itsmorphology, population, accompanying plant species, soil pH value, and did someexploration for its artificial propagation. The results showed that:(1) The aquatic fernin this place grew well, average plant height35cm, up to50cm, density60/m2,coverage80%, and associated with a variety of accompanying plants, where soil pHvalue6.32;water fern spores germinated into filaments after planting about13days,about20days, they formed pieces, and about50days, they formed matureheart-shaped prothallium, and archegonium and antheridium could be seen inside it,where contained egg and sperm, and spiral sperm can be seen shed from theantheridium, then sperm and egg combined to form zygote, and embryo formedthrough cell division, then the first and second spoon-shaped vegetative young leavescame out, and the third young leave began to form a plume crack. Leaves came out ata rate of1piece/3-7days, after about10vegetative leaves, sporophyll formed, but inthe later season for a new plant, sporophyll formed after only2-3vegetative leaves.Water fern seedling emerged in the field in June, and vegetative plant vigorous growthperiod is July and August, sporophyll came out quickly in September and October,spores matured in November and December, and debilitating period was January andFebruary in the next year.(2) Aquatic fern can be artificially propagated in a varietyof ways, such as spore sowing, ramets propagation and leaf in vitro culture. Collectingspores and sowing them in proper condition with suitable temperature, light, andwater may increase the spore germination rate. Water fern spores could germinate andgrow in medium with a broad pH value range from4.38to7.05. Paddy soil is themost suitable medium for spore germination and growth. Adding MS macroelementsto the culture medium also helps spore germination and growth. After one monthgermination, germinating spores should be transplanted to moist paddy soil in a largerspace to allow the sporophyte forming faster and growing better. Seperating ramets atthe sporophyte vigorous growth period, will provide enough space for growth.Aquatic fern plants could be induced from the trophophyll and sporophyll, whose induction rate was87.5%and15%respectively. Adding MS macroelements to themedium could improve the sporophyll induction rate, especially intemperature-controlled conditions. Temperature-controlled condition had morepositive effect on induction of new plant growth than room temperature condition;High frequency of new plants could be induced from trophophyll in water or mud,and the new induced plants should be timely transferred to the paddy soil in a largerspace to continue to grow. In short, the aquatic fern in this place grew well, severalmethods such as spore sowing, ramets propagation, and trophophyll or sporophyl invitro culture could rapidly amplify the number of water fern and stablize water fernpopulations.